[ifstream.cons] (original) (raw)

31 Input/output library [input.output]

31.10 File-based streams [file.streams]

31.10.4 Class template basic_ifstream [ifstream]

31.10.4.2 Constructors [ifstream.cons]

Effects: Initializes the base class withbasic_istream<charT, traits>(addressof(sb)) ([istream.cons]) and sb withbasic_filebuf<charT, traits>() ([filebuf.cons]).

explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);explicit basic_ifstream(const filesystem::path::value_type* s, ios_base::openmode mode = ios_base::in); // wide systems only; see [[fstream.syn]](fstream.syn "31.10.1 Header <fstream> synopsis")

Effects: Initializes the base class withbasic_istream<charT, traits>(addressof(sb)) ([istream.cons]) and sb withbasic_filebuf<charT, traits>() ([filebuf.cons]), then callsrdbuf()->open(s, mode | ios_base​::​in).

If that function returns a null pointer, callssetstate(failbit).

explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);

Effects: Equivalent to basic_ifstream(s.c_str(), mode).

template<class T> explicit basic_ifstream(const T& s, ios_base::openmode mode = ios_base::in);

Constraints: is_same_v<T, filesystem​::​path> is true.

Effects: Equivalent to basic_ifstream(s.c_str(), mode).

basic_ifstream(basic_ifstream&& rhs);

Effects: Move constructs the base class, and the contained basic_filebuf.

Then calls basic_istream<charT, traits>​::​set_rdbuf(​addressof(sb))to install the contained basic_filebuf.